Honing generally involves moving a honing tool reciprocatingly through a hole or bore of a workpiece, with an outer abrasive surface of the tool in abrading contact with the surface defining the hole or bore, and while rotating the tool. Typically, it is desired to impart very precise cylindricality and roundness to the surface of defining the hole, and a fine surface finish (cross-hatch pattern, etc.) may be sought. Any significant taper, barrel shape, skew, out of roundness, or other deviation is considered bad, and could result in scrapping of the workpiece. Cost is also typically important, and thus the consumption rate of honing tools (tool wear) is a concern.
Patterns of tool wear are also of concern, as if the abrasive surface of a honing tool wears unevenly, this may produce a corresponding unevenness or non-uniformity in the surface of the hole or bore being honed.
Some honing applications, particularly blind holes or bores, that is, holes that have an open end and an opposite closed or blind end, and stepped holes, can present a problem by preventing or limiting movements (overstroking) of the honing tool in one direction, particularly the direction beyond the closed or blind end, or the step. This can be a problem, as the portion of the abrasives on the end of the honing tool used for honing near or to the blind or stepped end of the hole are in abrading contact with the workpiece surface to for a greater extent of the honing stroke compared to the abrasives on the opposite end of the tool, resulting in uneven abrasive wear from end to end, particularly, more wear toward the free end or tip of the tool. The tool thus loses its original profile shape, e.g., cylindrical, such that workpiece holes honed with the tool will be correspondingly misshaped, e.g. choked or reduced in diameter adjacent to the blind end or step. This problem is increased when honing holes or bores in workpieces composed of very hard or tough materials, and to avoid this problem the abrasive elements of the honing tools, e.g. outer tubular members or sleeves, or the entire tools, must be replaced more frequently, such that tool consumption and resultant honing cost per workpiece is unacceptably high.
Thus, what is sought is a honing tool with improved wear resistance, which provides a capability for honing blind holes, and which overcomes one or more of the problems and shortcomings set forth above.